Double resonance calibration of g factor standards: Carbon fibers as a high precision standard
Abstract
The g factor of paramagnetic defects in commercial high performance carbon fibers was determined by a double resonance experiment based on the Overhauser shift due to hyperfine coupled protons. Our carbon fibers exhibit a single, narrow and perfectly Lorentzian shaped ESR line and a g factor slightly higher than gfree with g = 2.002644 =gfree · (1 + 162ppm) with a relative uncertainty of 15ppm . This precisely known g factor and their inertness qualify them as a high precision g factor standard for general purposes. The double resonance experiment for calibration is applicable to other potential standards with a hyperfine interaction averaged by a process with very short correlation time.
- Publication:
-
Journal of Magnetic Resonance
- Pub Date:
- April 2018
- DOI:
- Bibcode:
- 2018JMagR.289..100H
- Keywords:
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- g factor;
- Calibration;
- g standard;
- Chemical shift;
- Chemical shielding;
- Overhauser DNP;
- High-field EPR